Condensed Consolidating Financial Information - Balance Sheets (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Dec. 31, 2009
Current Assets:
Cash and cash equivalents	$ 461	$ 616	$ 518	$ 836
Restricted cash and securities	1,259	2
Receivables	337	264
Due from (to) affiliates	0	0
Other	104	90
Total Current Assets	2,161	972
Property, Plant and Equipment, net	5,117	5,302
Restricted Cash and Securities	121	120
Goodwill and Other Intangibles Assets, net	1,728	1,798
Investment in Subsidiaries	0	0
Other Assets, net	127	163
Total Assets	9,254	8,355
Current Liabilities:
Accounts payable	342	329
Current portion of long-term debt	265	180
Accrued payroll and employee benefits	77	84
Accrued interest	189	146
Current portion of deferred revenue	140	151
Other	90	66
Total Current Liabilities	1,103	956
Long-Term Debt, less current portion	7,420	6,268
Deferred Revenue, less current portion	742	736
Other Liabilities	512	552
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	(523)	(157)
Total Liabilities and Stockholders' Equity (Deficit)	9,254	8,355
Level 3 Communications, Inc.
Current Assets:
Cash and cash equivalents	44	173	171	236
Restricted cash and securities	0	0
Receivables	0	0
Due from (to) affiliates	12,635	11,927
Other	4	4
Total Current Assets	12,683	12,104
Property, Plant and Equipment, net	0	0
Restricted Cash and Securities	18	18
Goodwill and Other Intangibles Assets, net	0	0
Investment in Subsidiaries	(11,373)	(10,437)
Other Assets, net	13	9
Total Assets	1,341	1,694
Current Liabilities:
Accounts payable	1	1
Current portion of long-term debt	261	176
Accrued payroll and employee benefits	0	0
Accrued interest	55	47
Current portion of deferred revenue	0	0
Other	0	0
Total Current Liabilities	317	224
Long-Term Debt, less current portion	1,531	1,612
Deferred Revenue, less current portion	0	0
Other Liabilities	16	15
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	(523)	(157)
Total Liabilities and Stockholders' Equity (Deficit)	1,341	1,694
Level 3 Financing, Inc.
Current Assets:
Cash and cash equivalents	6	7	7	8
Restricted cash and securities	0	0
Receivables	0	0
Due from (to) affiliates	12,267	11,424
Other	11	10
Total Current Assets	12,284	11,441
Property, Plant and Equipment, net	0	0
Restricted Cash and Securities	0	0
Goodwill and Other Intangibles Assets, net	0	0
Investment in Subsidiaries	(18,891)	(17,176)
Other Assets, net	41	65
Total Assets	(6,566)	(5,670)
Current Liabilities:
Accounts payable	0	0
Current portion of long-term debt	0	0
Accrued payroll and employee benefits	0	0
Accrued interest	102	99
Current portion of deferred revenue	0	0
Other	1	1
Total Current Liabilities	103	100
Long-Term Debt, less current portion	4,609	4,564
Deferred Revenue, less current portion	0	0
Other Liabilities	99	107
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	(11,377)	(10,441)
Total Liabilities and Stockholders' Equity (Deficit)	(6,566)	(5,670)
Level 3 Communications, LLC
Current Assets:
Cash and cash equivalents	329	350	269	431
Restricted cash and securities	1	1
Receivables	95	46
Due from (to) affiliates	(27,304)	(26,093)
Other	54	41
Total Current Assets	(26,825)	(25,655)
Property, Plant and Equipment, net	2,824	2,937
Restricted Cash and Securities	22	21
Goodwill and Other Intangibles Assets, net	496	543
Investment in Subsidiaries	3,396	3,575
Other Assets, net	7	6
Total Assets	(20,080)	(18,573)
Current Liabilities:
Accounts payable	39	57
Current portion of long-term debt	2	2
Accrued payroll and employee benefits	71	78
Accrued interest	0	0
Current portion of deferred revenue	110	115
Other	57	65
Total Current Liabilities	279	317
Long-Term Debt, less current portion	23	24
Deferred Revenue, less current portion	684	673
Other Liabilities	150	154
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	(21,216)	(19,741)
Total Liabilities and Stockholders' Equity (Deficit)	(20,080)	(18,573)
Other Non-Guarantor Subsidiaries
Current Assets:
Cash and cash equivalents	82	86	71	161
Restricted cash and securities	1,258	1
Receivables	242	218
Due from (to) affiliates	2,402	2,742
Other	35	35
Total Current Assets	4,019	3,082
Property, Plant and Equipment, net	2,293	2,365
Restricted Cash and Securities	81	81
Goodwill and Other Intangibles Assets, net	1,232	1,255
Investment in Subsidiaries	0	0
Other Assets, net	66	83
Total Assets	7,691	6,866
Current Liabilities:
Accounts payable	302	271
Current portion of long-term debt	2	2
Accrued payroll and employee benefits	6	6
Accrued interest	32	0
Current portion of deferred revenue	30	36
Other	32	0
Total Current Liabilities	404	315
Long-Term Debt, less current portion	1,257	68
Deferred Revenue, less current portion	58	63
Other Liabilities	247	276
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	5,725	6,144
Total Liabilities and Stockholders' Equity (Deficit)	7,691	6,866
Eliminations
Current Assets:
Cash and cash equivalents	0	0	0	0
Restricted cash and securities	0	0
Receivables	0	0
Due from (to) affiliates	0	0
Other	0	0
Total Current Assets	0	0
Property, Plant and Equipment, net	0	0
Restricted Cash and Securities	0	0
Goodwill and Other Intangibles Assets, net	0	0
Investment in Subsidiaries	26,868	24,038
Other Assets, net	0	0
Total Assets	26,868	24,038
Current Liabilities:
Accounts payable	0	0
Current portion of long-term debt	0	0
Accrued payroll and employee benefits	0	0
Accrued interest	0	0
Current portion of deferred revenue	0	0
Other	0	0
Total Current Liabilities	0	0
Long-Term Debt, less current portion	0	0
Deferred Revenue, less current portion	0	0
Other Liabilities	0	0
Commitments and Contingencies
Total Stockholders' Equity (Deficit)	26,868	24,038
Total Liabilities and Stockholders' Equity (Deficit)	$ 26,868	$ 24,038